The present invention relates to a method that allows one or more stamping foils to be introduced into a system that advances the foil.
The present invention also relates to a device for implementing this insertion method.
The invention finds a particularly advantageous application in the field of stamping machines.
It is known practice for texts and/or patterns to be printed by stamping, that is by using pressure to apply to a sheet form medium , the colored or metalized film taken from one or more stamping foils which are commonly known as metalized foils. In the industry, such a transfer operation is usually performed using a vertical platen press into which the print supports are introduced sheet by sheet, while the foils are fed continuously via a foil drive system which advances them along a clearly determined feed path.
Traditionally, such a foil drive system combines a series of idling shafts which are installed along the entire feed path to guide the progress of the foils, with a number of advance shafts which are positioned in the downstream part of said feed path in order respectively to drive the forward movement of each of said foils. This in practice implies that, for their initial placement, each foil has to be partially wound around a great many elements in addition to passing through the platen press.
A good number of the idling shafts are difficult to access, especially those positioned in close proximity to the platen press. The same is true of the space between the plates of the press. In any event, the end result is that manual introduction of the foils proves to be a particularly complicated operation in such a drive system.
This is why insertion devices have been developed that are capable automatically of routing the foils from a starting point to a finishing point, both of which are relatively accessible. The starting and finishing points are situated respectively one on each side of the platen press.
Particularly well known is an insertion device which uses a bar mounted with a transverse translational mobility in a trajectory substantially parallel to the feed path of the foils. In concrete terms, in the region of the abovementioned start point, each foil is temporarily secured to the rod by means of adhesive tape. The rod then undergoes a mechanical translational movement along its movement trajectory, which causes the various foils to be pulled and therefore to deploy along their feed path. Once the finishing point has been reached, all the foils are detached from the rod by removing the adhesive tape.
This type of insertion device does, however, have the disadvantage of not being ergonomic enough given that the rod start and finishing points are in fact rarely easy to access. Indeed usually the starting point is situated in the lower part of the platen press, that is to say in a region that is particularly cluttered. The finishing point itself is positioned in the high part, that is to say in a region that is intrinsically difficult to access, to the point where it is often necessary to climb up on top of the platen press in order to reach it. Finally, attaching and detaching the foils to and from the rod are awkward operations because they have to be performed individually for each foil and because they entail manipulating adhesive tape each time.